Methyl dihydrojasmonate having the structure: ##STR2## and alkyl and alkylene homologues thereof defined according to the structures: ##STR3## or the generic structure: ##STR4## wherein n is 0 or 1 and wherein R is C.sub.1 -C.sub.4 alkyl and R'" represents C.sub.1 -C.sub.3 alkyl are valuable ingredients useful as medicinal drug intermediates and perfumery materials; for use in augmenting or enhancing the aroma of perfumes, perfumed articles such as nonionic, anionic, cationic or zwitterionic detergents or dryer-added fabric softener articles or colognes.
Methyl dihydrojasmonate has been previously shown to be prepared in United Kingdom Patent Specification No. 907,431 published on Oct. 3, 1962, according to the process: ##STR5## wherein R' is methyl or ethyl and R represents lower alkyl, and wherein R.sub.1 represents lower alkyl and M represents alkali metal such as potassium or sodium.
Furthermore, the prior art sets forth alkylidenylation reactions with cyclopentanone and unsaturated aldehydes according to the reaction sequence: ##STR6## (Vol. 78 Chemical Abstracts 59537k (abstract of Mekhtiev et al, Azerb. Khim. Zh. 1973 (1), 47-51)) and the reaction: ##STR7## (Vol. 79 Chemical Abstracts 78170t (abstract of Mekhtiev et al, Azerb. Khim. Zh. 1972 (4), 50-5)) wherein R is propyl or isopropyl.
German Offenlengungsschrift No. 27 32 107, published on Jan. 9, 1978, sets forth the reaction: ##STR8## (abstracted in Chem. Abstract Vol. 88, 169667a).
Nothing in the prior art, however, indicates the highly efficient reaction sequence leading to methyl dihydrojasmonate or lower alkyl homologues thereof according to the reaction sequence: ##STR9## or the reaction sequence: ##STR10## or the reaction sequence: ##STR11## or the reaction: ##STR12## wherein R is C.sub.1 -C.sub.4 alkyl; X is chloro or bromo; and n is 0 or 1.